Hot-air motor.



Patented May 7, I90l.

J. E. THOBNTONRI. J. P. LEA.

HOT AIR MOTOR.

(Applicntion filed Dec. 29, 1897.) (lo Indol.) 2 Shoots-Sheet l.

WITNESSES INVENTORS THE mums vzvzws co. wo'romuo. wAsumm-m n No. 673,462. Patented May 7,- l90l. J. E. THORNTON 8:. J. P. LEA.

HUT AIR MOTOR.

(Application filed Dec. 29, 1897.]v (I Io Iodal.) 2 $heets$haet 2.

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UNITED STATES PATENT OFFICE.

JOHN E. THORNTON AND JAMES P. LEA, OF ALTRINGHAM, ENGLAND.

HOT-Al R MOTO R.

SPECIFICATION formingpart of Letters Patent No. 673,462, dated May '7, 1901.

Application filed December 29, 1897. Serial No. 664,461. (No model.)

To ttZZ whom it may concern:

Be it known that we, JOHN EDWARD THORN- TON and JAMES POLLARD LEA,subjects of the Queen of Great Britain, and residents of Altringham, in the county of Chester, England, have invented certain new and useful Improvements in Hot-Air Motors, of which the following is a specification.

This invention relates to motors in which the motive power or force is obtained from the expansion of air or other gas or gases by heat, and is designed to provide a compact and reliable motor of this class. The-heat may be imparted to the said air, gas, or gases by transmission through the walls of suitably placed and formed passages, the primary source of heat being outside the motor-cylin- The original charge of air is in compression when the additional heat is imparted to it to increase its pressure.

A motor according to this invention will be fully described with reference to the accompanying drawings.

Figure 1 is a vertical section. transverse section on line 00 m, Fig. l. is a plan.

In the cylinder A is fitted at one end a trunk-piston B, capable of moving to and fro therein the greater part of its length, and at the other end an auxiliary disk or piston O with only a short travel or movement.

The cylinder A is accurately bored and is provided at or near the center with an annular chamber or recess D, forming a port for the inlet of cold air to the interior of the cylinder. The lower end is connected to an airchamber E, communicating bya port or pas sage F through the chamber D with the interior of the cylinder and provided with an air-inlet valve G, through which the necessary supply of fresh air is admitted. The upper end of the cylinder A is provided with air-passages h, leading to a heater H, and with an exhaust-valve K and exhaust port or passage in.

To the main pistonB is fitted, pivoted on the spindle b, an oscillating connecting-rod Z, which connects the piston B with the crank L. The crank L is placed inside the airchamber E, and the crank-shaft L projects Fig. 2 is a Fig. 3

through the walls of the air-chamber at either side, rotating in journals Z, which are packed to prevent the escape of air.

The heater H, which is in communication with the interior of the cylinder A through the air-passages h, is constructed with two concentric cylinders h h, the air-passages passing through the interior of theinner cylinder h and around the exterior of it and through the interior of the outer one 72.. A supply-pipe M supplies gas, oil, or vapor to a burner, which causes a flame to impinge upon the exterior of the outer cylinder 72. A combustion-chamber m is formed around the cylinder 71/ by a protecting-cover M, lined with asbestos or other non-conducting material. Instead of gas or oil solid fuel may be burned around the heating-cylinder h.

The inlet-valve G opens to admit fresh air when the pressure in the air-chamber E is reduced below the external atmospheric pressure by the return stroke of the piston B.

The exhaust-valve K is controlled by a cam N on one side the crank-shaft L, operating on a pivoted lever 01, connected to the valvespindle is by a connecting-rod n. The valve is closed by the spring is.

The auxiliary piston C in the upper end of the cylinder is operated and caused to move to and fro therein by a cam O on the crankshaft L, operating on apivoted lever P, which is connected With a second pivoted lever P by the connecting-rod p. The pivoted lever P rests against the end of the piston-rod O and moves the piston O in one direction, the internal pressure moving it back in the reverse direction, and the spring a maintains it in position against the cylinder-cover.

The cylinder is kept cool by a jacket R, filled with water.

The operation of the motor when running is as follows- The piston B being in the position shown in the drawings at the end of its stroke, the chamber or port D is uncovered and the cylinder filled with a fresh charge of air. On the return stroke of the piston B it travels to the position indicated by the dotted line y y, leaving the air-passage h uncovered, and compresses the'air in the cylinder and also draws a fresh charge of air into the chamber E through the inlet-valve G. The movement of the crank which returns the piston B also rotates the cam N, releasing the exhaust-valve K, which is closed by the spring When the piston B approaches the position indicated by the dotted line y y, the

cam O operates the levers P and P and moves the piston 0 toward the piston B. The pressure on the under side of the piston 0 being greater than the pressure on the upper side by reason of the presence on the upper side of the piston-rod O, the piston is returned to its elevated position by such pressure and the spring 0, thelatter retainingitin that position. This movement of the piston G forces the compressed air through the air-passages h to the heater H to the other side of the piston G and back again into the cylinder between the two pistons, the air being thus heated and its pressure increased. The increased force or pressure is exerted upon the piston B to drive it back and give motion to the crank L and crank-shaft L. This forward stroke of the piston B compresses the fresh charge of air in the chamber E, and the motion of the cam N opens the exhaust-valve K a little before the port or passage F is uncovered. Thus the heated air is allowed to escape and is all forced out through the exhaust-passage k by the inrnsh of the fresh charge of compressed air through the port F and annular passage or chamber D. The cycle of operations then recommences and continues during the running of the motor.

To start the motor, the aforesaid heater H is first raised toa suitable temperature. Then as the heat required is already in existence and stored in the walls of the passages it cannot fail to be given up to the compressed-air currents, and therefore the power is developed immediately and with absolute certainty. If the motor stands habitually with its piston at the full extent of its outward stroke, as shown in the drawings, then any means of giving the crank-shaft La moderately-quick movement for half a revolution or a little over would suffice to start the motor in either direction, the motor continuing to run in the direction in which such movement was given to it. As the motor may be standing for a more or less lengthened period ready to start at any moment, it maybe arranged that only the requisite amount of heat necessary to make up for radiation and other losses may be imparted to the heaterH at such times.

What we claim as ourinvention, and desire to protect by Letters Patent, is-

1. A motor operated by heated air or other gases comprising a cylinder A fitted with air inlet and exhaust passages and provided with air-passages leading toa heater, a heater H by which the air is heated and expanded, a main piston B working to and fro in the cylinder, an auxiliary piston Cwhich forces the I air through the heater a chamber E behind the main piston into which the fresh air is drawn andin which it is compressed by the return stroke of the main pistonB and a passage F and ports D leading from air-chamber E to the interior of the cylinder A substantially as described.

2. Ina motoroperated byheated air or other gases the combination with the cylinder A main piston B heater H and the auxiliary piston G for driving the air to and fro through the heater, of the crank L, the crank-shaft L the cam O on the crank-shaft, the pivoted lever P operated by thecam and the connecting-rodp and second pivoted leverp by which the auxiliary piston O is operated substantiallyas described.

3. In a motoroperated by heated air or other gases the combination with the cylinder A provided with an air-inlet passage D air-passages h leading to a heater, and exhaust-air passages K of a fresh-air chamber E placed at one end, a main piston B working to and fro in the cylinder, an auxiliary piston C for forcing the air to and fro through the heater, a heater H in which the air is heated and inlet-valve G for admitting fresh airto the airchamber, a crank L and crank-shaft L actuated by the piston, an exhaust-valve K for discharging the spent air,-a cam O on the crank-shaft and pivoted levers P P for operating the auxiliary piston and a cam N on the crankshaft and pivoted lever n for opening the exhaust-valve K substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

- J. E. THORNTON.

J. P. LEA. Witnesses:

J. OWDEN OBRIEN, R. OVENDALE. 

